How to initialize the Sound class in Python
Blender very rarely (if at all) instances from class.

Rather than add a new object with  ob = bpy.types.Object("blah") the blender way is to use the new method, or for images and sounds the load method of its data collection. eg bpy.data.objects.new("name", data) or bpy.data.sounds.load(filepath)

To load a new sound

snd = bpy.data.sounds.load("/path/to/soundfile")


python console, add a speaker and add sound.

&gt;&gt;&gt; D.speakers.new(
new()
BlendDataSpeakers.new(name)
Add a new speaker to the main database
&gt;&gt;&gt; D.speakers.new("xxx")
bpy.data.speakers['xxx']

&gt;&gt;&gt; D.speakers['xxx'].sound = D.sounds.load(
load()
BlendDataSounds.load(filepath, check_existing=False)
Add a new sound to the main database from a file
&gt;&gt;&gt; D.speakers['xxx'].sound = D.sounds.load("/tmp/xxx.mp3")
&gt;&gt;&gt;  speaker_obj = bpy.data.objects.new("speaker", D.speakers['xxx'])


Link to scene in 2.79 and prior

&gt;&gt;&gt; C.scene.objects.link(speaker_obj)


Alternatively with the operator, Add a new speaker object to the scene

bpy.ops.object.speaker_add(view_align=False, enter_editmode=False, location=(0, 0, 0), rotation=(0, 0, 0))
speaker_obj = context.object